Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:4.1.2.13 (aldolase)
3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The production of neuraminidase by a classical strain of Clostridium welchii (C. perfringens) type A was studied. Good yields were produced in 5% Proteose Peptone-water medium (PPW5); the enzyme was essentially extracellular but some further neuraminidase could be released by ultrasonic disintegration of the cells. This also released N-acyl neuraminic acid-aldolase (NAN-aldolase) and the degree to which this interferes with the assay for neuraminidase was evaluated. Forty-one British reference food-poisoning strains of C. welchii type A were examined for extracellular neuraminidase production in PPW5. Twelve of 17 strains that produce so-called heat-sensitive spores were neuraminidase positive whereas 20 of 24 strains that are non-haemolytic and produce very heat-resistant sporeswere neuraminidase negative. Variation was found in the ability to produce neuraminidase among strains of a single Hobbs' serotype; four Hobbs' type-13 strains produced neuraminidase but a fifth did not. Disruption of the cells of a Hobbs' type-2 strain that did not produce any extracellular neuraminidase released NAN-aldolase but there was no evidence of cell-associated neuraminidase. British food-poisoning strains of C. welchii type A thus include some that are clearly neuraminidase positive and some that still cannot be shown to produce neuraminidase. There is no correlation between lack of neuraminidase production and the ability to cause food poisoning, although the majority of non-haemolytic heat-resistant strains do not produce neuraminidase. It remains possible that neuraminidase may play a part in C. welchii gas gangrene; it is suggested that the ability to define neuraminidase-negative strains may now be of value in investigating this possibility.
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PMID:The production of neuraminidase by food poisoning strains of Clostridium welchii (C. perfringens). 16 69

The production of neuraminidase (EC 3.2.1.18) by a range of clostridial species was investigated with techniques previously developed to distinguish neuraminidase-negative and neuraminidase-positive strains of Clostridium perfringens (welchii). Large amounts of extracellular neuraminidase were produced by representative strains of C. perfringens and C. septicum in the test media. Under similar conditions, two strains each of C. chauvoei and C. tertium were found to produce small amounts of the enzyme. All of 12 strains of C. sordellii were clearly shown to produce neuraminidase, often in large amounts, but none of five strains of the closely related but non-pathogenic C. bifermentans had demonstrable neuraminidase activity. No neuraminidase was produced by C. novyi (oedematiens) types A-D (10 strains), C. tetani (6), C. botulinum types A, B, C or E (4), C. sporogenes (4), C. histolyticum (4) or by single strains of five other clostridial species. Clostridial neuraminidase was predominantly extracellular and was not calcium-dependent. The investigation took account of variations in growth and enzyme production in different media. It was necessary to prolong the neuraminidase-assay reaction time to 24 h and to monitor for the presence of NAN-aldolase (EC 4.1.3.3) to define true negatives. It is suggested that neuraminidase production may be of value in taxonomic studies and that its production by several pathogenic species of clostridia may be of interest in studies of pathogenicity and virulence.
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PMID:Neuraminidase production by clostridia. 21 Feb 77

A total of 256 S. pneumoniae strains, the causative agents of infectious processes with different localization, were studied for their virulence (in experiments on mice), neuraminidase and aldolase-protease activity (APA). In pneumococcal strains isolated 18-20 hours after intraperitoneal infection their virulence for mice increased, on the average, 1,000-fold and the average level of extracellular and cellular neuraminidase and APA increased 2- to 5-fold in comparison with the initial values. Pneumococcal strains causing acute pneumococcal infections with different localization, or the aggravation of such infections, exhibited higher virulence for mice and higher levels of neuraminidase and APA, while the inflammatory process at the period of clinical remissions was mainly maintained by S. pneumoniae cultures with low virulence.
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PMID:[The virulence of Streptococcus pneumoniae strains--the causative agents of pneumococcal infection at different sites]. 148 98

Mucinase enzymes were isolated and partially purified from the culture fluid of Vibrio cholerae grown in proteose peptone-colostrum medium. The mucinase complex contained neuraminidase, endo-beta-N-acetylhexosaminidase, nicotinamide-adenine-dinucleotidase and proteinases. Traces of phospholipase activity were detected but the complex lacked aldolase activity.
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PMID:Studies on the Vibrio cholerae mucinase complex. I. Enzymic activities associated with the complex. 302 45

The relation of neuraminidase to morbidity and mortality was examined in patients with Haemophilus influenzae, meningococcal, and pneumococcal meningitis. Ten strains of H. influenzae and eight strains of meningococci from infected cerebrospinal fluid (CSF) did not elaborate neuraminidase. Each of 27 strains of pneumococci from infected CSF elaborated both neuraminidase and N-acetylneuraminic acid (NANA) aldolase. There was no correlation between amount of neuraminidase secreted in vitro and survival of patients. Values for free and total NANA concentrations were derived from admission CSF samples of 63 patients with meningitis; 18 patients infected with Neisseria meningitidis, 10 with H. influenzae and 35 with Diplococcus pneumoniae. Mean values for total NANA were elevated in each type of bacterial meningitis; however, abnormal concentrations of free CSF NANA were detected only in 17 patients with pneumococcal meningitis. 11 of 18 patients with pneumococcal meningitis showing normal free CSF NANA concentrations were cured, whereas only 4 patients with abnormal free NANA levels survived without residua. Both coma and bacteremia occurred significantly more often among patients with elevated concentrations of free CSF NANA. The association of elevated concentrations of free CSF NANA with coma and with an adverse prognosis suggested that neuraminidase may be a factor in the pathogenesis of penumococcal meningitis.
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PMID:Neuraminidase activity in bacterial meningitis. 439 34

To characterize the true substrate for aldolase from Clostridium perfringens (optimum pH = 7.2) several experiments were carried out wherein the substrate Neu5Ac was generated in situ at pH 5.4 by the action of sialidase on its substrate Neu5Ac(alpha, 2 leads to 3) lactose. The alpha-anomer formed in this reaction was found to be split by aldolase at this pH into ManNAc and pyruvate. beta-Neu5Ac as such was not converted at pH 5.4. However, when it was first mutarotated until the equilibrium mixture alpha:beta = 7.2:92.8 was obtained, it could be split. Inhibition experiments suggested that Neu5Ac was bound to the enzyme in a conformation that strongly resembled that of its alpha-anomer. The open chain form of ManNAc which arose after the action of aldolase preferentially formed the alpha-anomer followed by a fast mutarotation.
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PMID:Configuration of substrate and products of N-acetylneuraminate pyruvate-lyase from Clostridium perfringens. 630 75

Serum sialic acid has been assayed enzymatically. The reaction includes neuraminidase hydrolysis of glycoprotein, cleavage of sialic acid to pyruvate by N-acetyl neuraminic acid (NANA)-aldolase, oxidation of pyruvate by pyruvate oxidase which produces hydrogen peroxide, and colorimetry of hydrogen peroxide using the peroxidase-p-chlorophenol-4-amino-antipyrine method. This method showed good correlation between a chemical method (r = 0.984), good recovery (98.8%) and good reproducibility (within-run-precision: 1.0% C.V.; day-to-day precision: 1.9% C.V). Intrinsic serum pyruvate produces an equimolar positive effect. The normal value range is 1.94 +/- 0.29 mmol/l (mean +/- S.D.,n = 24).
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PMID:Enzymatic assay of serum sialic acid. 747 82

The 9-amino or 9-N-acyl-5-trifluoroacetyl methyl alpha-ketosides (1a-c) and their 2,3-didehydro analogs (2a-c) have been synthesized through Neu5Ac aldolase-catalyzed aldol reaction of 6-azido-2-benzyloxycarbonylamino-2-deoxy-D-mannose with sodium pyruvate. The six compounds were investigated as inhibitors of sialidase from influenza virus. Compound 2b, a 2,3-didehydro type, showed the most potent inhibitory activity (IC50 > 7.8 microM) against the enzyme, whereas, compounds 1a-c as the methyl alpha-glycosides were found to be practically inactive (IC50 > 100 microM).
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PMID:Chemoenzymatic synthesis of neuraminic acid analogs structurally varied at C-5 and C-9 as potential inhibitors of the sialidase from influenza virus. 858 91

Statistically significant charge clusters (basic, acidic, or of mixed charge) in tertiary protein structures are identified by new methods from a large representative collection of protein structures. About 10% of protein structures show at least one charge cluster, mostly of mixed type involving about equally anionic and cationic residues. Positive charge clusters are very rare. Negative (or histidine-acidic) charge clusters often coordinate calcium, or magnesium or zinc ions [e.g., thermolysin (PDB code: 3tln), mannose-binding protein (2msb), aminopeptidase (1amp)]. Mixed-charge clusters are prominent at interchain contacts where they stabilize quaternary protein formation [e.g., glutathione S-transferase (2gst), catalase (8act), and fructose-1,6-bisphosphate aldolase (1fba)]. They are also involved in protein-protein interaction and in substrate binding. For example, the mixed-charge cluster of aspartate carbamoyl-transferase (8atc) envelops the aspartate carbonyl substrate in a flexible manner (alternating tense and relaxed states) where charge associations can vary from weak to strong. Other proteins with charge clusters include the P450 cytochrome family (BM-3, Terp, Cam), several flavocytochromes, neuraminidase, hemagglutinin, the photosynthetic reaction center, and annexin. In each case in Table 2 we discuss the possible role of the charge clusters with respect to protein structure and function.
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PMID:Clusters of charged residues in protein three-dimensional structures. 871 Aug 74

Good sperm motility in normozoospermic men was associated with high bound and total sialic acid (SA) and pyruvate concentrations in the seminal plasma, as well as high endogenous (sperm) pyruvate concentrations. The presence of sialidase in the seminal plasma was also demonstrated for the first time. The results suggest that SA is metabolized to pyruvate by a N-acetylneuraminic acid (NANA)-aldolase in the seminal plasma and that pyruvate subsequently serves as an energy source for sperm.
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PMID:Sialic acid in semen of normozoospermic men. 973 Apr 38


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